Wireless communication technologies have seen tremendous growth in the last few years. This growth has been fueled in part by the freedom of movement offered by wireless technologies and the greatly improved quality of voice and data communications over the wireless medium. Improved quality of voice services along with the addition of data services have had and will continue to have a significant effect on the communicating public.
FIG. 1 is a block diagram that shows a Push-to-Talk over Cellular (PoC) service and an Instant Messaging (IM) service, both operating in a wireless communication system 100.
An Instant Messaging (IM) service uses an IM service to exchange messages with other IM clients 108. Even though IM service was developed to exchange text based information, there is no restriction to carrying other types of information such as audio clips, images, etc. Also, there is no restriction on a user regarding what to transmit and when to transmit. Typically, the information is not streamed from the sender to receiver. Users may transmit at any time, as there is no concept of floor control.
A Push-to-Talk over Cellular (PoC) service establishes a half-duplex audio communication channel between a group of PoC users or clients, 104, as shown in FIG. 1. At most, one member of a PoC group has the right to transmit at any time and all other members receive the transmitted information. A floor control mechanism is used to arbitrate requests for the right to transmit from different members of the group. The talk burst generated by the sender is packetized and is streamed to the receivers.
It is difficult for a PoC service to interwork with an IM service because of the explicit floor control mechanism of the PoC service. Floor control is used in the PoC service to ensure that only one client transmits audio packets at a time. In contrast, the IM service has no concept of floor control, as each member of the IM group may transmit at any time. The PoC service packetizes the audio and then streams the audio to other participants. This is not the case in the IM service, where the IM client buffers the audio packets and creates an audio clip, which is then distributed to other IM session participants. Since users in one group may desire to communicate with users in the other service, there is a need for a method and apparatus to allow the PoC service to interwork with the IM service. This may be accomplished with a method and apparatus for implicit floor control in push-to-talk over cellular systems.